Disposable absorbent articles, such as disposable diapers and the like, usually have an absorbent panel containing superabsorbent polymers to increase the absorbent capacity of the panel while reducing the bulkiness of the article. For example, see U.S. Pat. No. 3,670,731 to Harmon.
Particular absorbent panel constructions contain a zoned region of superabsorbent material in a selected portion of the panel in an attempt to make efficient use of the superabsorbent material. U.S. Pat. No. 4,333,463 to Holtman discloses an absorbent pad which contains a zoned region of superabsorbent material in its front upper or lower portion. U.S. Pat. No. 4,381,783 to Elias describes an absorbent article wherein one or more separate and distinct moisture-permeable cells or pockets containing superabsorbent particles are provided in a crotch region of the article. U.S. Pat. No. 4,685,915 to Hasse et al. suggests application of a zoned deposit of superabsorbent polymers in a central portion of an absorbent article. U.S. Pat. No. 5,009,650 to Bernardin teaches an absorbent structure wherein superabsorbent material is located more at a rearward portion of an absorbent structure.
A number of methods and apparatus have been proposed to manufacture absorbent pad structures having a zoned deposit of superabsorbent material. U.S. Pat. No. 4,087,506 to Cook et al. discloses a method of producing a fluid absorbent web wherein superabsorbent polymer particles are applied onto a central zone of a moving web by means of a spreader. U.S. Pat. No. 4,551,191 to Kock et al. describes an arrangement wherein gas-entrained superabsorbent polymer particles are discharged through a nozzle having a predetermined width in a direction parallel to the direction of travel of the moving porous web so that they are uniformly deposited on the predetermined width portion of the web.
U.S. Pat. No. 4,800,102 to Takada discloses the use of a rotating screen disc having openings of various shapes at intervals, which disc is positioned between a superabsorbent supplier and a moving web so that superabsorbent polymer particles are intermittently deposited on the web at the intervals and patterns corresponding to the openings in the disc. U.S. Pat. Nos. 4,927,346 and 5,017,324 to Kaiser et al. respectively disclose an apparatus and a method for depositing superabsorbent polymer particles into a pad of fibrous material in a forming chamber. A controller selectively directs gas-entrained polymer particles either to a supply hopper or to the fibrous material to produce discrete patterns of superabsorbent polymers along the pad.
U.S. Pat. No. 4,927,582 to Bryson teaches another method for depositing superabsorbent particles into a pad in a forming chamber. The flow velocity of the superabsorbent polymer particles into the forming chamber is controlled so that a selected distribution of the polymer particles is achieved within the fibrous material deposited in the forming chamber. U.S. Pat. No. 5,028,224 to Pieper et al. teaches forming a split stream of superabsorbent material particles by centrifugal segregating means. The split stream is intermittently delivered into a forming chamber so that zoned regions of higher polymer density are formed within the fibrous material.